Dramatic Cheirurus ingricus Russian Ordovician trilobite

Description: Coming from the nearly half billion year old Middle Ordovician Asery Level deposits of the Wolchow River region near Saint Petersburg, Russia, this is an example of a member of the Order Phacopida, Family Cheiruridae called Cheirurus ingricus. These are very dramatic trilobites, with expansive genal and pygidial spines. This one is in a prone position, crawling over its matrix, with the dramatic genal spines spread freestanding for all to see. Its caramel-colored Calcite shell is well set off by the white limestone matrix. Due to the fragility of the spines, I have chosen to keep it secure in the shipping box as it was received from Russia. Nevertheless, the spectacular spines are easily seen in this "Emperor of the Phacopids".